Consumer, military and industrial ruggedized portable electronics devices and other portable electrical applications still mainly rely on lithium ion and other battery technologies. Conventional batteries are heavy relative to their energy capacity. Portable fuel cell systems, however, offer higher energy densities, particularly when they use a liquid fuel.
The portability constrains fuel cell system design and adds challenging design criteria such as weight, space, and managing elevated fuel cell system temperatures while adhering to portable electronics device skin temperature standards. Thermally active electrochemical power generation in a portable package thus presents a complex series of interweaving technical problems; a solution for one problem is often in conflict with one or more others. For example, adding a pump to a stationary fuel cell system represents a trivial addition to total weight and total power consumption. Adding a pump to a portable system, however, can add as much as ten percent to the total weight and total power consumption. As another example, in a portable reformed methanol fuel cell system, fuel cell performance improves through the use of a higher operating temperature fuel cell; yet the higher operating temperature threatens to increase the surface temperature of a packaged system, resulting in the requirement to use added thermal packaging and heat management, which increases size, weight and potentially energy. Techniques that increase the viability, cost effectiveness, noise reduction and efficiency of portable fuel cell systems are desirable.